The present invention relates generally to the art of power supplies, and more particularly concerns switching regulator type power supplies.
Size restrictions, if any, on a given power supply usually control whether the power supply uses a transformer or a switching regulator to produce the desired output. The smaller size supplies will use a switching regulator while a transformer is generally utilized where size and weight restrictions are not severe. Unfortunately, the switching regulator power supply is usually limited in its voltage and current capabilities, due to the operating limits of the switching transistor. This is especially true if a short switching time is required, which is usually the case where supply efficiency is an important consideration. Large transient startup currents are of particular concern in such power supplys and must be carefully dissipated. In some applications, startup can be implemented by an auxiliary power supply, but such a solution is not practical where size and operating efficiency are high design priorities.
Accordingly, it is a general object of the present invention to provide a switching regulator power supply which overcomes one or more of the disadvantages of the prior art discussed above.
It is an additional object of the present invention to provide such a power supply which is capable of operating on both AC and DC input voltages.
It is another object of the present invention to provide such a power supply which operates at a relatively high efficiency over a wide range of input voltages, both AC and DC.
It is a further object of the present invention to provide such a power supply which requires a minimum amount of space.
It is another object of the present invention to provide such a power supply having a relatively high current capability combined with fast switching characteristics, without an auxiliary power supply.